Rated 5 out of 5 stars
I came across stumbleupon quite recently, and besides enjoying the site, the toolbark add on makes it easier to discover new things and add new bookmarks. It has become a must have in my firefox. It's easy to personalize and use, and it's also very helpful. Besides it doesn't crash my browser and I can hide/show it with a simple keyboard shortcut. One of my favs!This review is for a previous version of the add-on (4.11).